1. Field of the Invention
The present invention relates to a pixel interpolation circuit, a pixel interpolation method, and a recording medium, used in an imaging system etc., employing a single-panel color imaging system.
2. Related Art
It has become standard for digital cameras to use a single-panel imaging system using an image acquisition device employing a Bayer array as a pixel array. When image signals are acquired based upon Bayer data, which is object image data acquired by an image acquisition device that employs a Bayer array, color information (pixel values) for each pixel, other than that of the color filter arranged at the respective pixels in the image acquisition device that employs a Bayer array has to be interpolated. In particular, G pixel information affects brightness information. Accordingly, the G pixel information affects the image signal resolution and the contour sharpness.
As conventional techniques for interpolating a G pixel for each of the interpolation target pixels in the Bayer data (R pixels and B pixels having no G pixel information), the techniques described in Unexamined Japanese Patent Application No. 2000-278703 and Unexamined Japanese Patent Application No. 2006-135564 are known. In these conventional techniques, G pixel interpolation is performed for each interpolation target pixel, giving consideration to the correlation among the pixels around the interpolation target pixels in the Bayer data.
However, these conventional techniques refer to only G pixels around the interpolation target pixel when G pixels are interpolated. This leads to a small amount of pixel information being used as reference pixel for interpolating the G pixel for each interpolation target pixel.